The present invention relates to a closed loop control system for enabling standing and walking by paraplegic or quadriplegic persons. So far as is known this has never been achieved prior to the completion and testing of the present invention. Typical prior art consists of powered exoskeletal apparatus of the general type disclosed in Mizen U.S. Pat. No. 3,449,769. Such prior art devices include a structure which is worn by a person and which includes sensor assemblies adapted to respond to normal movement of the wearer. Output signals from the sensor assemblies are amplified and used to drive servomotors which power the exoskeletal structure.
While the above described prior art enables a man to perform tasks otherwise beyond his physical ability, there has been no means for enabling walking through the use of muscles which are totally paralyzed. That objective is achieved by the present invention which grew out of early research as described in an article entitled "Walking Away from Paralysis" appearing in Discover magazine, May, 1981, page 26 et seq and in an article entitled "Microprocessor Controlled Stimulation in Paralyzed Muscle", IEEE NAECON Record (1979), pages 198 through 210. The achievement of such walking involves the use of devices for feedback controlled stimulation of paralyzed muscle, as generally taught in Petrofsky et al Ser. No. 417,934, Petrofsky et al Ser. No. 417,938 now U.S. Pat. No. 4,421,336, Petrofsky et al Ser. No. 417,935 now U.S. Pat. No. 4,480,830 and Petrofsky et al Ser. No. 444,647.